A solid electrolytic capacitor has such advantages as small dimension, large capacitance, and superior frequency characteristics, and can play a role of decoupling for a power source circuit of a Central Processing Unit (CPU).
Generally, a plurality of capacitor units can be stacked on a lead frame to form a solid electrolytic capacitor having a high capacitance. FIG. 25 is a local schematic view of a solid electrolytic capacitor. Referring to FIG. 25, in a solid electrolytic capacitor 400, multiple capacitor units 410 are stacked on a lead frame 420. Each capacitor unit 410 has a cathode portion 412 and an anode portion 414. The lead frame 420 has a cathode terminal 422 and an anode terminal 424. After the stacking is completed, multiple anode portions 414 are electrically connected with anode terminals 424 through anode solder joints 430. However, the solid electrolytic capacitor 400 further needs to perform subsequent heat treatment test, and in this case, external water vapor W and heat energy H easily enable the anode solder joints 430 to be oxidized, be insulated, or peel, resulting in an undesirable electrically connection between the multiple anode portions 414, and capacitance will be greatly reduced at an equal proportion.
Furthermore, if the external water vapor W infiltrates into a cathode portion 412 of the capacitor unit 410, problems that false capacitance and energy consumed by the solid electrolytic capacitor 400 within unit time due to heat generation (DF, Dissipation Factor) are increased, and reliability of the solid electrolytic capacitor 400 is reduced are caused.